Various industries involve systems for dispensing material, such as dry solids, onto conveying devices. In the hydrocarbon exploration and production industries, for example, materials are often dispensed from storage units onto conveyor belts for delivery to another location or system. One exemplary scenario often utilizing material storage units and conveyors is a hydraulic fracturing well site requiring the use of proppant or sand. In many frac job sites, a material storage unit, such as the Frac Sander by National Oilwell Varco, Inc, is used to dispense the sand or proppant onto a conveyor for delivery to another component, such as a blender.
Presently known systems and techniques for dispending material onto conveying devices may have one or more drawbacks. For example, as illustrated in FIG. 1, the material 32 often overflows off the sides of the conveyor 40 as it is being discharged from the dispensing unit 30. For another example, there is typically an insufficient barrier between the material dispenser and the conveyor to prevent wind or other external disturbances from displacing the material as it is being discharged onto the conveyor. Because it is often difficult or impossible to determine the actual volume of material ultimately carried by the conveyor, it is impossible to accurately meter or control the discharge rate onto the conveyor. In some instances, attempts are made to control the discharge rate by only slightly opening the discharge gate or varying the open position of the discharge gate, which can be difficult and ineffective. Also, the conveyor is often run at full or near-full speeds without interruption in order to deliver a sufficient quantity of material, causing significant undesirable friction, wear and dust.
It should be understood that the above-described discussion is provided for illustrative purposes only and is not intended to limit the scope or subject matter of the appended claims or those of any related patent application or patent. Thus, none of the appended claims or claims of any related application or patent should be limited by the above discussion or construed to address, include or exclude each or any of the cited examples, features and/or disadvantages, merely because of the mention thereof herein.
Accordingly, there exists a need for improved systems, apparatus and methods useful to assist in controlling the discharge of material onto a conveyor having one or more of the attributes or capabilities described or shown in, or as may be apparent from, the other portions of this patent.